A Liquid Electrolyte with De-Solvated Lithium Ions for Lithium-Metal Battery

Traditional liquid electrolytes used in rechargeable batteries, fuel cells, and electrochemical capacitors composed of solvents, anions, and solvents solvated cations (e.g., lithium ions, Li+), follow classic “cations with solvation” electrolyte configuration and can be defined as “cations solvated electrolytes.” In these electrolytes, the de-solvation processes of solvated cations only occur when the cations inserted-deposited on the electrodes’ surface. Here, different from traditional electrolytes, a new liquid electrolyte with de-solvated Li+ was discovered (“Li+ de-solvated electrolyte”), since it merely composed of inactive “frozen-like” solvent and crystal-like salt solute. Inspiringly, its electrochemical stability was remarkably improved (extended to 4.5 V for “Li+ de-solvated ether-based electrolyte”). Ultra-stable high-energy-density lithium-metal batteries (LiNi0.8Co0.1Mn0.1O2//Li) were achieved (half-cell: 140 mAh g−1 after 830 cycles; full-cell: 170 mAh g−1 after 200 cycles under twice excessed Li). It is also surprising that this does not present any cathode-electrolyte interface (CEI) layer on the cycled NCM-811 surface benefit from the “Li+ de-solvated electrolyte.”